Grand Caravan FWD V6-3.3L VIN 3 Flex Fuel (2002)
Vehicle Speed Sensor: Description and Operation
Vehicle Speed and Distance
Description
The PCM receives a signal from the TCM and the transaxle output speed sensor over the bus communication line.
Operation
4 Speed Automatic Transmission
The 4 speed automatic Transmission Control Module (TCM) supplies the speed input to the PCM. The PCM determines acceleration rates. The speed
control software in the PCM uses vehicle speed and acceleration to control the set speed.
For more information for the 4 speed automatic transmission please refer to the Output Speed Sensor See: Transmission Control Systems/Sensors and
Switches - Transmission and Drivetrain/Sensors and Switches - A/T/Transmission Speed Sensor
3 Speed Automatic Transmission
Vehicles with a 3 speed automatic or manual transmission have a Vehicle Speed Sensor (VSS) mounted to an adapter near the transmission output shaft.
The sensor is driven through the adapter by a speedometer pinion gear. The VSS pulse signal is monitored by the PCM to determine vehicle speed and to
maintain speed control set speed.
